Degradation of Aroclor 1221 in soil by a hybrid pseudomonad

The hybrid Pseudomonas cepacia strain JHR22 was tested for its ability to degrade Aroclor 1221 in soil. The influence of supplements--mineral salts and trace elements--on the degradation was investigated. Disappearance of Aroclor 1221 congeners, occurrence of metabolites, and release of chloride were measured under different conditions. After 45 days the hybrid organism, strain JHR22, was still present at high numbers in soil, independently of whether the soil had been sterilized prior to inoculation or not. There was only a minor difference in degradation efficiency between sterilized and untreated soil with about 70% release of chloride when 10(7) cells/g soil were inoculated. The whole hybrid pathway, originating from three different strains, was found to be stable under the conditions tested. Mineral salts did not significantly affect the degradation rate or survival of the hybrid strain.